A current advancement on the role of lignin as sustainable reinforcement material in biopolymeric blends

Recently, the demand for biodegradable, eco-friendly and sustainable alternatives has been on the increase. Although numerous biopolymers such as cellulose, starch, plants proteins and polylactic acid, etc., have been used to produce bioplastics, the outcomes need more improvement to suit different applications. This paper comprehensively maps the expanding academic territory using lignin as a reinforcement material to improve biopolymers-based materials' properties. A brief discussion on the chronological development of lignin, types, isolation, physical and chemical modifications was presented. Also, the role of lignin in biopolymeric blends such as starch, polylactic acids, plants proteins, polyhydroxy butyrate and polyamides was reviewed. Finally, the review extensively and critically discusses the current findings on lignin/biopolymers blends in various industrial applications, including wood adhesives, adsorbent for toxic heavy metal removal, production of carbon materials, dispersant medium, flame retardant and storage materials, etc., and highlighted the possible applications of lignin in biofuel, hydrocarbon, lubricant, renewable chemical, and smart materials.